Research On Frequency Regulation For A Power System With Battery Energy Storage

In order to solve the environmental pollution and energy shortage problems caused by traditional fossil fuel power generation,renewable energy sources generation have been developed largely in recent years.As the renewable energy power generation is unstable and can`t supply constant power,it will challenge the security and stability of the power grid.Meanwhile,the slow reaction and low ramping rate of traditional generations fail to meet the needs of power system’s fast development.The energy storage technology possesses the abilities of fast response and good power tracking capacities,which can provide effective frequency regulation services.Being more efficient than the transitional generation,it may serve as a new solution to problems of frequency regulation.Firstly,this paper introduces the mechanism and basic concepts of power system frequency regulation,and study the dynamic mathematical model of each part of the system.Based on the analysis of the principle of battery energy storage and the traditional frequency regulation model,a battery energy storage assisted frequency modulation model is established in MATLAB / Simulink.The system is simulated in both the step load disturbance and the continuous load disturbance of wind power.By observing the frequency of the system and the tie line power exchange response,the comparative analysis of battery energy storage on the effect of frequency regulation,the results indicates the need for battery energy storage technology.Then,in order to procure sufficient reserve power for Load Frequency Control,a novel battery utilization method is proposed to compensate the rate shortage of the transitional generation.In the method,a battery is driven by the component of LFC signal which cannot be responded by existing conventional generator.Through comparison study with conventional battery control method,it is clarified that the proposed method can efficiently improve LFC performance under the large amount of renewable energy sources interconnection.Finally,a method of calculating the capacity of the battery energy storage system is introduced by using the standard deviation of the frequency standard.The calculation shows that the battery energy supply needs a smaller capacity to achieve the same frequency regulation performance as conventional generation needs.